Anticline or unconformity in Thornthwaite Forest

At first sight, this looked like an unconformity. Vertical layers in the shale with a horizontal layer on top. The lowest horizontal layer seemed to be quartz.

But looking from a different angle, it seems that the vertical curves round to become the horizontal. I actually think this is a very tight anticline that has been broken through its peak.

Steam locomotive pistons

The steam goes through the pipe from the boiler into the piston where it pushes. The piston is connected to an incompressible rod that is attached the wheel, which means that the horizontal motion of the piston pushed on the wheel. The heavy engine pushes down on the wheel so much that there is enough friction for the wheel not to slip. The push of the piston can thus turn the wheel. The drive wheel is coupled to the front wheel. I guess that this means the friction at the front can be utilised as well.

Steam locomotive boiler

I've seen models of this set up before but never really understood what they were trying to show. The picture is of the front of a steam locomotive with its front open. This space opens into the chimney above. Smoke goes up the chimney,not steam, but I'd been left with the impression that steam was coming through the pipes shown. In fact, very hot air and smoke particles from the firebox are coming through. There is water behind the white wall in the top picture. The arrangement means that thermal energy is applied to the tank of water over a much larger surface area and so the process is more efficient. Water boils and steam builds up at the top. Then the two substantial pipes that come from the middle top and go down each side actually carry the steam down to the pistons. https://www.explainthatstuff.com/steamengines.html

A brake on the railway pedal car

The pedal carriage on the Penryn railway had a brake that was a semi-circular metal band that was forced onto the wheel by a lever. The ratio on the lever looks to be about 10:1. Suppose a burly quarry worker could lift 30kg with one hand. That would be a 300N force. The brake would be applied by 3000N. Eight 100kg workers in a heavy car would be at least 1 1/2 tonne. That would mean acceleration of a = F/m = 3000/1500 = 2 m/s/s. That's a fast decrease in speed so is probably unrealistic. The brake is semi-circular to give a large surface area to increase the friction since friction is a contact force.

Reflective clothing at the Watchtree Seasonal Series

We went running in the dark last night. I understand that the reflective tape on my shoes must work by Total Internal Reflection, but how do they make it? I found this lovely explanation https://www.chinareflective.com/faqs/How_does_reflective_fabric_work.html The one described uses tiny glass beads part-coated in aluminium to make sure that the light bounces around inside the sphere and then bounces back the way it came.

Pedal power on the railway

This amazing pedal car for a quarry railway was in the museum at Penryn Castle. One detail is hard to see in the photographs of the back of the carriage. Each of the 4 foot cranks from the front is connected to the drive shaft at 90 degrees to the others. This means that there will always be drive from one of the shafts and enough momentum to push the opposite shaft back into position. It's a bit like a 4-cylinder engine.

A leap year can of worms

The more I read about leap years the more I found out.
1. I knew that the calendar had been reformed in the Middle Ages and that the British had been late to adopt this but I didn't know the reason for the reform. It has to do with the correct calculation of the date for Easter, which was calculated from the Spring Equinox.
2. The reason that this was out of sync was that a year lasts 365.2422 days not 356.25 days. The calendar was slipping out of sync with the sky by about a day every 200 years. I knew that the solution was to drop the leap year day at the turn of the century but that didn't happen on the Millennium. You drop 3 leap years every 400 years.
3. The year is called a "tropical year" https://en.wikipedia.org/wiki/Tropical_year. The definition involves precession so that will take a bit of thinking about.
4. There is an astronomical year numbering system that involves giving a Year 0 to the usual western calendar dates. https://en.wikipedia.org/wiki/Astronomical_year_numbering